Secure data communication between a central database and a remote or mobile node typically rely upon secure data handling techniques such as encryption, but provide only limited control over the location of the remote node. In particular, the sheer mobility of a remote node makes it very difficult to protect against unauthorized use of equipment. For example, one scenario where protection is required is when an aircraft is on the ground or in hostile territory, where copying can be performed illegally or without authorization. Additionally, when individual passenger units are in use, a tape intended for authorized viewing could be stolen.
Some conventional systems for transmitting secure data messages provide some kind of control over hardware in a non-secure environment, where location affects the type of authorization granted mobile nodes. However, these systems are vulnerable because geographical information is not conveyed in a secure manner.